How to do them

Beginner version
Some do find the balance and position of the shoulder stand challenging at first. Here is a way to still get the benefit as you get comfortable with the position.
Lie with your right shoulder against a wall on a cushioned surface like a carpet or a Yoga mat. Raise your legs and hips off of the ground as you rotate facing your head away from the wall. Bend your legs at the waist so your feet are on the wall for support.
When in position, your weight is supported primarily by your shoulders, your arms, and the back of your neck. Your chin should be tucked snugly against your sternum and you should feel a compression in your lower neck and your thyroid area. As you get comfortable, use just one leg for support. Start with 10-30 seconds and work up to a full minute.
Regular version
Lie on your back and raise your body and legs upward, supporting them with your hands on your mid-back. Your weight will be supported primarily by your shoulders, neck, and the back of your upper arms. Hold the position for 1-2 minutes.